Valorization of spent coffee grounds as biosorbent for the retention of fluoxetine from water a cost-effective alternative to activated carbon

Abstract

The goal of this study is to evaluate and to compare the effectiveness of spent coffee grounds (SCG), a waste-based biosorbent, and granular activated carbon (GAC) for the removal of fluoxetine, a widely consumed psychiatric pharmaceutical. Equilibrium measurements performed in batch experiments allowed to determine the adsorption capacity of the materials under evaluation. GAC had by far the highest adsorption capacity, 215.0 mg/g, while SCG showed a maximum uptake of 14.31 mg/g. The cost analysis performed revealed that SCG, although presenting lower adsorption capacity, is the most economically feasible adsorbent, with a cost of 0.77 per gram of fluoxetine removed, that is quite lower when compared to that of GAC, 1.16 /g. This study demonstrates that SCG is a waste-based biosorbent that may be successfully applied and be cost-effective for the removal of fluoxetine from water.